Field of the Invention
This invention relates generally to interventional devices and, more particularly, to interventional devices having an integrated embolic filter, as well as methods of making and using the same.
Description of the Related Art
The vascular bed supplies a constant flow of oxygen-rich blood to the organs. In diseased vessels, blockages can develop that can reduce blood flow to the organs and cause adverse clinical symptoms up to and including fatality. Diseased vessels can comprise a range of material from early-stage thrombosis to late-stage calcified plaque.
Angioplasty can be described as a catheter-based procedure performed by a physician to open up a stenosed vessel and restore blood flow. An entry site can be opened, for example, in the patient's groin, arm, or hand, and a guide wire and catheter can be advanced under fluoroscopic guidance to the location of the blockage. A catheter having a small balloon adjacent its distal end can be advanced under fluoroscopic guidance until the balloon lies within the stenosed region. The balloon can be then inflated and deflated one or more times to expand the stenosed region of the artery.
Angioplasty is one example of a vascular intervention that can release embolic particles down-stream from a stenosed or otherwise compromised location during intervention. These embolic particles can result in adverse clinical consequences. It has been shown beneficial to trap these embolic particles to prevent them from traveling downstream with blood flow to the capillary bed (e.g., Baim D S. Wahr D, George B, et al., Randomized trial of a distal embolic protection device during percutaneous intervention of saphenous vein aorta-coronary bypass grafts, Circulation 2002; 105:1285-90).
In addition to balloon angioplasty, stenoses can also be treated with stents and with mechanical thrombectomy devices. These devices are also prone to releasing embolic particles downstream from a stenosed location during intervention.
Systems available today used to catch these embolic particles consist primarily of distal filter systems or occlusion balloon systems. Distal filter systems are on guidewires, as are distal balloon occlusion systems. Proximal balloon occlusion systems are on a guide catheter or sheath. These systems suffer shortcomings related to simplicity of use. Embolic protection guidewires also suffer from flexibility and stability problems that render the protected angioplasty procedure relatively more difficult in many cases. In the case of saphenous vein grafts, the problems relate specifically to aorto-ostial lesions, where the guidewire may not be long enough to provide support, or distal vein graft lesions, where there can be not enough of a landing zone for the filter. The latter can be a problem as currently available filter systems can have a considerable distance between the treatment balloon and the distal filter. This distance can be a problem not only in distal vein graft lesions, but also in arterial stenoses in which there can be a side branch immediately after the stenoses. In such cases, the filter can often be deployed only distal to the side branch, thus leaving the side branch unprotected from embolic particles.
Accordingly, a need exists for improved interventional devices having an integrated embolic filter as well as methods for making an using the same.